From DE 10 2012 202 272 A1 a generic rotor of a supercharging device with a compressor wheel and a turbine wheel fastened thereon is known. Between the compressor wheel and the turbine wheel a heat shield is arranged, which subdivides a hollow space that exists between the compressor wheel and the turbine wheel into two hollow spaces. In these two hollow spaces a sub-pressure, in particular a vacuum, is provided, so that the turbine wheel solely because of the vacuum is held on the compressor wheel by way of the heat shield.
From DE 10 2008 048 135 A1 an exhaust gas turbocharger is known, which comprises a particular rotor geometry which is designed in such a manner that vibrations excited by the rotor are in a sub-critical frequency range. This serves to achieve that resonances do not become problematic up to the strength limit of the rotor.
Generally, a rotor of a supercharging device, for example of an exhaust gas turbocharger, usually consists of a compressor wheel, a shaft and a turbine wheel. This applies in particular to such embodiments in which the rotor via the shaft is located in a bearing housing that is located between a turbine housing respectively a compressor housing. A connection between the turbine wheel respectively the compressor wheel and the shaft is often effected by means of welding, which is advantageous in particular in the case of thin shafts. In the case of thicker shafts or in the case of a compressor wheel arranged directly on the turbine wheel welding however is not possible or only to a limited extent. For this reason, fastening of the turbine wheel to the compressor wheel by means of sub-pressure is recommended for example in DE 10 2012 202 272 A1. Disadvantageous with such an embodiment however is that with a diminishing sub-pressure there is the risk of the turbine wheel detaching from the compressor wheel and thus the risk of the rotor breaking apart, which because of the high rotational speeds of the rotor often results in a total destruction of the supercharging device.